Sound reproducing device



Dec. 25, 1934- H. R. VAN DEVENTER SOUND REPRODUCING DEVICE 2 Sheets-Sheet 1 Filed April '7, 1952 INVENTOR Filed April '1, 1952 2 Sheets-Shet 2 llllll INVENTOR UNITED STATES PATENT oFncE 1,985,390 SOUND narnonoome m-zvroa Harry R. Van Deventer, New York, N. Y., assignor to Patent Engineering Corporation, a corporation of Delaware Application April 1, 1932, Serial No. 603,792

9 Claims. (01. 179-110) This invention relates to improvements in sound reproducing devices as commonly employed in connection with radio receiving sets, loud speakers, talking motion picture machines and the like and has for its principal object the production of a simple, eflicient unit structure for the reproduction of sound waves from an electrical or similar type of source.

Another object of the invention is to provide a device of this character for use in relatively small cabinetsin which it is impossible to'mount the ordinary type of cone speaker having a diaphragm sufliciently large enough to faithfully produce sound waves in suflicient volume.

A further object of the invention is to provide a device of this character in which the supporting frame constitutes a perforated ornamental front for the device and supports the driving member which may be of any suitable type.

The invention consists substantially in the construction, combination, location and relative arrangement of parts, all as will be more fully hereinafter set forth as shown by the accompanying drawings and finally pointed'out in the appended claims.

The embodiment of the invention shown in Figures 1, 2 and 3 hereof is particularly appli-. cable to small radio receiving sets of the general type described in the co-pending application Serial No. 570,292 filed October 22nd, 1931 and the embodiments shown in Figures 4 and 5 are also applicable to such sets and for use in connection with any type of set or other device with which a loud speaker iscommonly employed.

The invention will be described as utilizing a piezo electric device as a driver for operating the speaker diaphragm as said piezo electric device is particularly .compact and eflicient when used in the manner herein described. Said piezo electric device may be of any suitable type and construction, suchfor example as the device shown and described in- U. S. Patent No. 1,802,783 dated April 28, 1931.

, In the accompanying drawings:

Figure 1 is a side elevation of a radio receiving set chassis showing two diaphragms mounted thereon and connected to a piezo electric crystal;

Figure 2 is a sectional view on the line 2-2 of Figure 1;

Figure ,3 is a sectional view on the line 3-3, Figure 2;

Figure 4 is a front view of a loud speaker embodying the invention, and

Figure 5 is a sectional view on the line 5-5 of Figure 4. I

It has been found that increased efficiency results from actuating the diaphragm of the devicefrom the front thereof and two types of construction will be shown herein by way of illustration.

The first type of construction is that shown'in Figures 1 to 3 inclusive in which the numeral 10 denotes a supporting frame upon which the diaphragm or diaphragms are mounted and which also supports the piezo electric crystal hereinafter termed the crystal.

The frame 10 is preferably made of metal formed to the desired shape in any suitable manner and may constitute the chassis of a radio receiving set.

The diaphragm-11 is slightly dished as shown in Figure 2 so that the center thereof is depressed inwardly and the diaphragm is secured to a frame 12 which is mounted upon the supporting frame 10 by means of screws 13.

The frame 10 is provided w'th a horizontally disposed base plate 14 which is secured to the sidewalls of the frame in any suitable manner, the said side walls extending downwardly as shown at 15, 15 and turned outwardly to provide the supporting feet 16.16.

The downwardly extending side walls of the frame 10 have cutaway portions '17, 1'7 therein to permit of the laterally and upwardly extending actuating arms 18, 18 which are connected to the free vibratory end 19 of the piezo electric crystal 20. These arms extend upwardly in front of the respective diaphragms to which they are connected and connect at their upper extremities 21 by means of a bolt 22 and spacer 23 to the center of the diaphragms. Itwill be understood that the connection and arrangement of each diaphragm are the same and while two diaphragms are shown, for the sake of illustration, only one may be used.

One end of the piezo electric crystal 20 is rigidly secured to the base plate 14 by means of the clamp 24.

A pair of wires (not shown) is connected to the piezo electric crystal and when suitable current is impressed thereon the crystal operates in the manner described in the aforesaid patent and will vibrate the diaphragms connected thereto.

It will be observed that by the arrangement just shown a piezo electric crystal is mounted underneath the base plate of the supporting as more fully disclosed in connection with the pending application Serial Number 603,789, filed April 7, 1932.

The modification shown in Figures 4 and 5 shows a unit loud speaker which may be mounted upon the type of chassis shown in Figure 1 or on the face of the usual radio cabinet or other device in which loud speakers are commonly associated.

Here the supporting frame 10 forms a front] ing arm 29 secured to the free end of the crystal.

The frame 10 is provided with a centrally disposed flattened portion 30 in order to supply a mounting place for the crystal which may be covered by the cap 31 or may be secured to the frame in any suitable manner, such as the screws 32.

Positioned on the flattened portion 30 of the supporting frame and preferably integral therewith is a lug 33 forming a support to which the crystal 20 is secured and in which it is rigidly held.

The frame immediately undemeath of the fiattened portion 30 is provided with an aperture 34 through which the arm 29 passes.

The wires 35, 36 connect with the crystal and extend downwardly as shown in Figure 5 between the frame and the diaphragm of the loud speaker and are finally brought through the hole 3'7 in the diaphragm and may be connected to the circuit for operating the speaker.

The complete unit speaker as just described may be mounted in a suitable cabinet, a wall of which is shown at 38 by the usual screws 39.

The front of the supporting frame 10 may be perforated as shown at 40 in Figure 5 in order, to permit the sound from the diaphragm to find egress while at the same time theframe serves to surround and protect the diaphragm from mechanical injury and acts as an ornamental grill.

Although the invention has been disclosed in connection with the specific details of preferred embodiments thereof it must be understood that such details are not intended to be limitative of the invention except insofar as set forth in the accompanying claims.

What is claimed is:

1. A sound reproducing device comprising a rigid non-vibratory supporting frame, a diaphragm dished inwardly towards said frame and supported thereby, and a piezo electric crystal having an actuating arm secured thereto and entering the concave side of said diaphragm at substantially the center thereof, said crystal being supported on said frame.

2. A sound reproducing device comprising a rigid non-vibratory supporting frame, a diaphragm dished inwardly towards said frame and supported thereby, a piezo electric crystal mounted subjacent said diaphragm and having a rigid actuating arm entering the concave side of said diaphragm at substantially the center thereof, said crystal being supported on said frame.

3. A sound reproducing device comprising a rigid non-vibratory frame having a rigid base plate, a diaphragm dished inwardly towards said frame and supported thereby, a piezo-electric crystal mounted on the underside of said plate, a rigid actuating arm secured to said crystal, said arm extending laterally and upwardly and having its extremity entering the concave side of said diaphragm and secured thereto.

4. A sound reproducing device comprising a frame having a solid base and open sides, a pair of diaphragms having their outer edges secured to said sides and dished portions extending into the openings therein, driving means for said diaphragms positioned below said base and secured thereto, and a pair of arms extending laterally' and upwardly from said driving means and connected to the front side of said diaphragms at the center thereof.

5. A sound reproducing device comprising a frame, a diaphragm supported thereby, a piezo electric crystal supported on said-frame in front of said diaphragm and an actuating arm secured to said crystal and to the front of said diaphragm.

6. A sound reproducing device comprising a frame adapted to form a front casing for the device, said frame having an annular rim portion forming a diaphragm support, a diaphragm secured to said rim, 9. piezo electric crystal mounted on said casing in front of said diaphragm, and an actuating arm connected to said crystal and said diaphragm.

7. A sound reproducing device comprising a frame adapted'to form a front casing for the device, said frame having an annular rim portion and a centrally disposed flat portion forming a support, a diaphragm clamped to said rim portion, a piezo electric crystal secured to said support, and an actuating arm connected to said crystal and diaphragm. F

8. A sound reproducing device comprising a frame adapted to form a front casing for the device, said frame having an annular rim portion and a centrally disposed flat portion forming a support, a diaphragm clamped to said rim portion, a piezo electric crystal secured to said support, an actuating arm passing through the plane of said frame connected to said crystal and diaphragm, and a removable cap enclosing said crystal secured to the front of said frame.

9. A sound reproducing device comprising a frame constituting a perforated ornamental front for the device, a lug integral with said frame, a piezo electric crystal secured to said lug and having its plane surface overlaying a portion of the front of said frame, a diaphragm peripherally secured to said frame on the rear edge thereof, an actuating arm connected to said crystal and diaphragm, and a cap enclosing said crystal and secured to said frame.

HARRY R. VAN DEVENTER. 

